484 
Proceedings of Royal Society of Edinburgh. [sess. 
Habitat. — From iceberg, lat. 74° 48' 4" N., long. 54° 52' 8" E., 
August 1872 (Grunow); Cape Wankarema (Cleve and Moller! 
Cleve !) ; Tindingen, Franz Josefs Land ; Kara (Cleve). 
C. capensis. Grun., Denk. Wien. Ak ., 1884, p. 86, pi. iv. (D), 
fig. 29. — Diam. '032 mm. Surface with slight circular undulation 
about the semiradius. Central space circular, about of diam. 
broad, distinct, with a few isolated granules at its centre. Mark- 
ings punctiform, smallest towards the border; rows straight or 
with slight bendings, inconspicuously fasciculate ; apiculi numerous, 
distinct, frequently arranged in a double row. Border sharply 
defined, hyaline. — Cleve and Moller, Diat ., No. 197. 
Distinguished from C. bipticatus, C. pellucidus , and C. bengalensis 
by its central space, subfasciculate rows, and apiculi. 
Habitat.— Brackish water, Baaken Biver, S. Africa (Grunow). 
C. bioculatus. Grun., Denk. Wien. Ak ., 1884, p. 107, pi. iii. (C), 
fig. 30; pi. iv. (D), fig. 1. — Diam. *02 to -03 mm. Surface convex, 
with faint concentric undulations. Central space subcircular, 
bearing two large conspicuous round granules, wdth evident central 
dot. Markings rounded, punctiform, least crowded towards the 
centre; rows subparallel in inconspicuous fasciculi, 18 to 22 in 
•01 mm. ; apiculi small, but evident, close to the border, numerous, 
subregular. 
In specimens from the Kara Sea and Cape Wankarema, N. Siberia, 
the markings and apiculi are more distant. 
Habitat. — Franz Josefs Land (Grunow). 
Yar. exigua. Grun., ibid., p. 108, pi. iv. (D), fig. 2. — Diam. # 012 
to ’015 mm. Central space minute, the large round granule single, 
or sometimes two of unequal sizes, the one indistinct. Markings 
less evident; rows 24 to 26 in *01 mm.; apiculi minute, 4 in 
•01 mm. 
Habitat. — Franz Josefs Land (Grunow). 
C. semipennatus. Grun., Denk. Wien. Ak., 1884, p. 83. — Diam. 
about '0305 mm. Central space absent or subobsolete. Markings 
rounded, or obtusely angular, granular; towards the centre 4, decreas- 
ing uniformly but considerably towards the border; rows fasciculate, 
